Dry mouth or xerostomia is an acute or chronic condition primarily caused by the lack of saliva. It may be caused by an underlying disease, such as Sjögren's syndrome, dehydration, trauma to the salivary glands, consumption of alcohol, or a side effect to medications. It has been identified as a condition increasing in the general population. Roughly 15% to 20% of young adults complain of oral dryness, and 30-40% of people ages 60-80 complain of oral dryness.
Xerostomia may cause several complications in patients. Saliva may be decreased, and may be foamy, thick and ropy. The tongue may be dry, fissured, lobulated, and may be infected with various bacteria and yeasts. Cheeks are often dry, dull and pale. The decreased moisture in the mouth creates difficulties in eating, as the chewing and swallowing of food is exacerbated by the lack of saliva. This also interferes with a person's ability to taste food, and produce speech. Furthermore, a moist mouth is beneficial in intimate human relations, which may also suffer as a result of dry mouth.
Patients suffering from xerostomia also suffer from extensive dental decay, e.g., caries, including areas not usually prone to decay, such as the lower incisors and roots. One possible explanation is that pellicle, which is present in saliva, provides a protective barrier between acids and a tooth surface, and such a barrier is reduced in the absence of saliva.
There are numerous products available to alleviate dry mouth, including oral moisturizing rinses, gels and synthetic saliva sprays, but there are few products which provide an anticaries effect. Current oral products for the treatment of dry mouth require high concentrations of fluoride to lower their risk of developing caries.
There is a continuing need to develop oral care compositions and methods to treat people suffering from dry mouth. There is also a continuing need to develop oral care compositions and methods to inhibit the development of caries in persons suffering from dry mouth. There is also a continuing need to develop oral care compositions which may aid in the consumption of foods, and production of speech in persons suffering from dry mouth.